1. Field of the Invention
The present invention relates, in general, to washing machines having drying apparatuses to dry laundry and, more particularly, to a washing machine having a drying apparatus, in which the drying apparatus quickly dries hot, humid air flowing from a water tub during a drying-mode operation, thus reducing a drying time and saving electricity while drying laundry during the drying-mode operation.
2. Description of the Related Art
Generally, washing machines are classified into vertical shaft-type washing machines in which a rotary tub is installed in a cabinet along a vertical axis of the cabinet, and drum-type washing machines in which a rotary tub is installed in a cabinet along a horizontal axis of the cabinet. To dry wet laundry after washing, some conventional washing machines have drying apparatuses, regardless of the types of the washing machines. For ease of description, the present invention relating to the drying apparatus will be described herein below, with reference to drum-type washing machines having drying apparatuses.
In a conventional drum-type washing machine, a rotary tub horizontally set in a cabinet is rotated around a horizontal axis of the cabinet in opposite directions, thus repeatedly moving laundry, seated on an internal surface of the rotary tub, upward together with washing water. Eventually, the laundry rises and drops from a raised position to a bottom in an interior of the rotary tub due to gravity, and thereby washing the laundry.
The conventional drum-type washing machine further includes a water tub installed in the cabinet and containing washing water therein, with the rotary tub rotatably installed in the water tub to wash the laundry. A door is mounted by a hinge to a front surface of the cabinet allowing a user to place and remove the laundry into and from the rotary tub. The conventional drum-type washing machine further includes a drying apparatus to dry the wet laundry after the laundry has been washed, rinsed and spin-dried.
The conventional drying apparatus for the drum-type washing machines includes an air duct provided on an outer surface of the water tub forming an air circulation circuit, in cooperation with an interior of the water tub, so that air used to dry the wet laundry circulates through the air circulation circuit which is a closed system, during a drying-mode operation of the drying apparatus. A blower fan and a heater are installed in the air duct. The conventional drying apparatus for the drum-type washing machines further includes a condensing nozzle provided in the air duct to condense vapor in the high temperature humid air produced while the air passed through the wet laundry to dry the laundry. In brief, the condensing nozzle of the drying apparatus sprays water from a plurality of spraying holes thereof to the humid air condensing the vapor from the air, thus dehumidifying the air while reducing the temperature of the air. Therefore, the condensing nozzle provides dry air of low temperature.
In the conventional drum-type washing machine, a drying-mode operation to dry the wet laundry is executed by the drying apparatus after the laundry within the rotary tub has been completely washed, rinsed and spin-dried through a washing-mode operation, a rinsing-mode operation and a spin-drying-mode operation. To dry the wet laundry, both the blower fan and the heater installed in the air duct of the drying apparatus are turned on, so that the dry air of low temperature from the condensing nozzle flows to the heater of the drying apparatus. The heater thus heats the dry air of low temperature making the dry air of high temperature. Thereafter, the dry air of high temperature passes through the wet laundry placed in the rotary tub, changing into humid air of high temperature while absorbing water from the wet laundry. Thereafter, the humid air of high temperature flows to the condensing nozzle, so that the air is dehumidified providing dry air of low temperature again. The above-mentioned circulation of the air in the air circulation circuit continues for a lengthy predetermined period of time drying the wet laundry placed in the rotary tub.
However, because the conventional drying apparatus for the drum-type washing machines has a single air path extending from a lower end to an upper end of the air duct having the condensing nozzle, the conventional drying apparatus has the following problems. Due to the single air path within the air duct, the humid air of high temperature flowing into the air duct contacts water sprayed from the condensing nozzle, thus being dehumidified. Therefore, the conventional drying apparatus does not efficiently condense the vapor from the humid air within a limited time, so the drying efficiency of the conventional drying apparatus is remarkably reduced.
Furthermore, in the conventional drying apparatus for the drum-type washing machines, the spraying holes of the condensing nozzle are open downward, so that water is sprayed downward from the spraying holes coming into contact with the humid air. The condensing efficiency of the condensing nozzle is thus reduced.
Furthermore, when a pressure of the water which is fed to the condensing nozzle of the conventional drying apparatus is low, water droplets produced by spraying of the water from the condensing nozzle becomes larger in size, so that specific surface areas of the water droplets which contact with the humid air of high temperature are reduced. In the above state, the conventional drying apparatus does not achieve a desired condensing efficiency.
Furthermore, the conventional drying apparatus for the drum-type washing machines is designed to change the humid air of high temperature into dry air by using only the condensing nozzle. Therefore, the humidity of the air may not be reduced to a desired low level capable of efficiently drying the wet laundry.
Therefore, the conventional drying apparatus for the drum-type washing machines requires a long time to dry the wet laundry, thereby increasing electricity consumption. The laundry drying performance of the drum-type washing machines having the conventional drying apparatuses is thus deteriorated.